本文選題：鈦合金 + 磨損行為��； 參考：《江蘇大學(xué)》2016年博士論文

【摘要】：鈦合金通常被認為具有差的摩擦學(xué)特性,使其應(yīng)用范圍受到了很大的限制。隨著鈦合金的應(yīng)用領(lǐng)域不斷擴展,對其摩擦磨損性能的研究受到越來越多的關(guān)注。目前,國內(nèi)外對鈦合金摩擦磨損性能的研究尚不夠全面和深入。本文系統(tǒng)研究了TC4和TC11兩種典型鈦合金在不同滑動速度和介質(zhì)條件下的摩擦磨損行為和磨損機理,探討了鈦合金室溫下磨損行為的影響因素以及不同滑動條件下鈦合金的磨損機制及其轉(zhuǎn)變,深入研究了鈦合金摩擦層及摩擦氧化物在磨損過程中的作用及機理,并通過雙滑動磨損試驗驗證了摩擦氧化物的作用。此項研究具有重要的理論意義和實際工業(yè)應(yīng)用價值。結(jié)果表明:TC4和TC11兩種鈦合金的摩擦磨損行為和磨損機理隨滑動速度的變化具有共性。鈦合金的磨損率隨滑動速度升高呈現(xiàn)出顯著變化。隨著滑動速度從0.5 m/s增加至4 m/s,磨損速率先降低,在0.75 m/s發(fā)生轉(zhuǎn)折,然后快速升高,在2.68 m/s達到最大值,最后再次降低,在4 m/s達到最小值。在相同滑動條件下TC4合金的磨損率均略高于TC11合金。同樣,磨損機理隨著滑動速度升高也發(fā)生顯著變化,0.75 m/s時主要為粘著磨損、磨粒磨損和氧化磨損;2.68 m/s時為金屬剝層磨損;4 m/s時為輕微-氧化磨損。研究發(fā)現(xiàn):鈦合金并不總具有較差的耐磨性,而是隨滑動條件變化呈現(xiàn)出兩種磨損狀態(tài):輕微磨損和嚴重磨損。輕微磨損和嚴重磨損在滑動速度0.5-4 m/s范圍內(nèi)交替出現(xiàn),并發(fā)生轉(zhuǎn)變。在0.75-2.68 m/s速度范圍內(nèi),隨著載荷增加,發(fā)生輕微-嚴重磨損轉(zhuǎn)變;而隨滑動速度從2.68 m/s增加到4 m/s,發(fā)生嚴重-輕微磨損轉(zhuǎn)變。后者表明鈦合金“不符合Wilson和Apas的輕微-嚴重磨損轉(zhuǎn)變的臨界溫度準則”,表現(xiàn)出與其它合金不同的特殊摩擦磨損特征。環(huán)境介質(zhì)對鈦合金磨損行為和機制有著顯著影響,腐蝕和磨損之間存在明顯的相互促進作用。在模擬海水中的磨損率始終最高,其次是純水中磨損率,空氣中磨損率最低。鈦合金在空氣條件下的磨損機理為粘著磨損和磨粒磨損,并伴有一定程度的氧化磨損;純水介質(zhì)中為磨粒磨損;模擬海水條件下為疲勞磨損和磨粒磨損。鈦合金在室溫條件下大氣環(huán)境中形成的摩擦層通�？梢苑譃閮深�:一般速度下的機械混合層和超高速度下的原位氧化物層。含摩擦氧化物的機械混合層被認為具有保護性。輕微磨損和嚴重磨損被認為與機械混合層中滑動誘發(fā)形成的摩擦氧化物的出現(xiàn)和消失相對應(yīng)。這與傳統(tǒng)觀點認為的鈦合金摩擦氧化物無保護性不同。采用雙滑動磨損試驗驗證了室溫條件下鈦合金在4 m/s速度下滑動產(chǎn)生的摩擦氧化層具有顯著的保護作用。通過對前人研究成果和本研究實驗結(jié)果的分析,初步弄清了鈦合金室溫下磨損行為的影響因素,并隨著滑動速度變化將其區(qū)分為三個主要影響區(qū):(1)較低速度下的絕熱剪切帶(ASB)和機械混合層(MML)影響區(qū);(2)中等速度下的塑性變形和MML影響區(qū);(3)高速下的塑性變形和原位氧化層影響區(qū)。并給出了鈦合金室溫下隨滑動速度和載荷變化的磨損機制圖。隨著滑動速度增加,磨損機制分別為粘著、磨粒和氧化磨損,剝層磨損,輕微-氧化磨損,嚴重-氧化磨損以及塑性擠出磨損。不同滑動速度下磨損影響區(qū)的轉(zhuǎn)變導(dǎo)致了磨損機理發(fā)生改變,最終使得磨損行為發(fā)生變化。
[Abstract]:Titanium alloys are generally considered to have poor tribological properties, and the application scope of titanium alloys is greatly limited. With the continuous expansion of the application field of titanium alloys, more and more attention has been paid to the research on the friction and wear properties of titanium alloys. At present, the research on the friction and wear properties of titanium alloys at home and abroad is not comprehensive and deep. The friction and wear behavior and wear mechanism of two typical titanium alloys, TC4 and TC11 under different sliding speeds and medium conditions, are discussed. The influencing factors of wear behavior at room temperature and the wear mechanism and transformation of titanium alloys under different sliding conditions are discussed. The wear process of titanium alloy friction layer and friction oxide in the wear process is deeply studied. The effect and mechanism of the two sliding wear tests are verified by the double sliding wear test. This study has important theoretical significance and practical application value. The results show that the friction and wear behavior and wear mechanism of the two kinds of titanium alloys of TC4 and TC11 have common characteristics with the change of sliding velocity. The wear rate of titanium alloy varies with the sliding velocity. As the sliding speed increases from 0.5 m/s to 4 m/s, the wear rate decreases first, the wear rate decreases at 0.75 m/s, then increases rapidly, reaches the maximum at 2.68 m/s, and finally decreases again at 4 m/s. The wear rate of TC4 alloy is slightly higher than that of the TC11 alloy under the same sliding condition. The wear mechanism is also along with the wear mechanism. The increase of sliding speed also changed significantly. 0.75 m/s was mainly adhesive wear, abrasive wear and oxidation wear, metal peeling wear at 2.68 m/s and slight oxidation wear at 4 m/s. It was found that titanium alloy did not always have poor wear resistance, but showed two wear states with change of sliding conditions: slight wear and severity. Wear. Slight wear and severe wear occur alternately and change within the range of sliding speed 0.5-4 m/s. Within the speed range of 0.75-2.68 m/s, a slight severe wear transition occurs with the increase of load, while the sliding velocity increases from 2.68 m/s to 4 m/s, with a severe slight wear transition. The latter indicates that the titanium alloy "does not conform to Wilson and Ap." The critical temperature criterion for the slight severe wear transition of as shows the special friction and wear characteristics different from other alloys. The environmental medium has a significant influence on the wear behavior and mechanism of titanium alloy, and there is a significant mutual promotion between corrosion and wear. The wear rate in the simulated seawater is always the highest, followed by the wear in pure water. The wear rate of the air is the lowest. The wear mechanism of titanium alloy under air conditions is adhesion wear and abrasive wear, with a certain degree of oxidation wear, and abrasive wear in pure water medium, fatigue wear and abrasive wear under simulated seawater conditions. The friction layers formed in the atmosphere environment of titanium alloy at room temperature are usually divided. Two categories: mechanical mixing layer under general speed and in situ oxide layer under high velocity. The mechanical mixing layer containing friction oxides is considered to be protective. Slight wear and severe wear are considered to correspond to the occurrence and loss of the friction oxides formed in the mechanical mixing layer. The friction oxide of gold is not different. Double sliding wear test has been used to verify that the friction oxidation layer of titanium alloy at room temperature under 4 m/s velocity has significant protective effect. By analyzing the results of previous studies and the results of this study, the factors affecting the wear behavior at room temperature are clarified. With the change of the sliding velocity, it is divided into three main areas: (1) the adiabatic shear band (ASB) and the mechanical mixing layer (MML) in the lower velocity; (2) the plastic deformation and the MML influence zone at the medium speed; (3) the plastic deformation and the in situ oxidation layer under the high speed. Wear mechanism, with the increase of sliding speed, wear mechanisms are adhesive, abrasive and oxidation wear, peeling wear, slight oxidation wear, serious oxidation wear and plastic extrusion wear. The change of wear mechanism at different sliding speed leads to the change of wear mechanism, and finally the wear behavior changes.

【學(xué)位授予單位】：江蘇大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2016
【分類號】：TG146.23
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本文編號：1891741